Vulcanizer and method of vulcanizing



June 30,1931. E. BLAKER VULCANIZER AND METHOD OF VULCANIZING Filed July19, 1923 zo'schedule of temperature and pressure;

, f tion in its preferred form', part"being* broken 1 I v f to admitcompressedair jand steam to the in:

jector'19, wherein th'eyjare intimately mixedl I and sothat they pas'sas a"compo'site'fluid the inletlnanifold'l lg from which they are I'Patented c1931 ERNEST lBLAlKER,

o L A zEeIA -D DYOFQW NI i G- Application filed .l'u1y719, 1228' SerialNo} "293,910. l

This invention relates to the vulcanization of rubber articles inmixture of gases such as 1 air andsteamias iirthe case oi employing" vsteam at a suitable"partiahpressure to g1ve' 5 the desired vulcanizingtemperature and air 7 i at a suitablepartial-pressure to provide a totalpressure o-fair and steam adequate to compact the article. 1' V Invulcaniz'ing inner tubes upon, iriandrels; for eXample,-it is desirabletof'pro'vide'thor ough and uniform; admixture" of the air" and steamthroughoutltheinteriorof the vulcanizerv from the beginning oftheoperation', while the pressure is being'built up, in order is to avoidunequal heat-softening and unequal vulcanization of; the articles, andmy chief objects are to provide improved procedure and apparatus forthat purpose and to provide a suitable ratio of the fluids'and animproved The single figure of i the accompanying drawing is a sideelevation offapparatus embodying and a'dapted-to-carry out myinvenfllaway'and insectio'nl- 1 a Referringto thedrawing, 10 is ahorizontal vulcaiiizer'of theusualsingle-wall construe tion'and11is ahinged door'at one end there of. The work, here" shown as consisting'of30 inner tubes '12; 12buil't'upon cylindrical mm 1 drelsj12, 12,is'mounted' upon a wheeled Utruck'13. "The tubes 12'have theirrespective ends tightly bound to the mandrel s' with moisttape,thefintermediate portion ofthe tube be.;

ing unconfined and exposed. a a

' Positioned inside the vulcanizer' 10-.a'l'ong the bottom thereofisaninlet manifoldlt comprising a horizontal-pipe having its up vperside formed with apertures 15, 15,ianda similar pipe 16 formed withapertures 17,17 on its under side ispo'sitionedalong the top ofthevulcanizing chamber'and comprises an" outlet manifold therefor.

The inlet manifold 14c.v

's connected at its middle with-Va supply pipe 18which leads through thevulcanizer wall from the outlet port of an inject0r19. The outletvmanifold 16 is connecteda t its middle with'a pipe 20 which extendsthrough the vulcanizer wall- 5 to the suction-inlet port of the injectorl9.

I A Vent pipe 21 providedwitha'shut oif valve 21 branches fromth'e'pi-pe'20', and the latter, a between the-vent pipe 21'and thevulcanizer 1 is provided with a'shut-ofi' valve 22. "Beyon i thevent-plpe 21 the pipe-20 is providedwith' OE'AKRoN, 0mm ss-mma momeeoonnioii COMPANY; or NEW YYORK,)N.1-Y.,1A CORPORATIONOF NEW; YORK fluidthrough the pipe"2Oftowardthe-vul I canizer', and'between saidcheck-valve; and-,

the-"injectorilQ thepip 20visconnect'ed to a high p'ressure' air line245 the latterheir-1g; provided witha shut-ofi-va1ve '25." Thepressure-inlet port of the injector 19 is connected to a'high-pressu'resteamline 26 which? is pr'o' vided with a shut-off ival ve '27. TheV1114 cania'erg 10 is provided with a drain-pipej28 'leadlng to asteam-trap 29=,'andalso'with temp'erature and pressure gauges 30 and 31re spectively:

In the operation of the apparatus; after p the work" has b'een wheeledinto*-the=-vul@10 canizer the door; ll is closed and sealed; the V valve21 in the vent-pipe'21-iselosedgfand I V ,1 the valve 22 is opened orallowed; to iremain The valves 25;-and 27 are then opened openadistributed throughout thelengtlr of the v'ul'aj fflowingfromrsaid"injector; aThearr'angement' is such that the air'andsteam are iiitimately;

mixed" before they enter the vulcanize'r; 'anl' by efiecting withdrawalof'air' fromthetop of thevulcanizer as the'compo'site fluidenters jw Ithe i bottom the'reoflvI- obtain a uniform dis tribution of .the"composite? fluid within the" i vulcanizer, and-"any oti said fluid-fwhich may be drawn off through the pipe 2O is returned j '7 1 tothe-vulcanizer' by reason of the closed oir- 1 I v cu'it comprising the-ipipes' 1'8,-

and} injec tor19. 1 U

The valves 25:, '27-'xpreferably are opened 1 to such extent Withrelation to each other that the air-steam mixture Within the vulcanizerattains a temperature of 220 and a pressure of pounds in about 7minutes. The airvalve 25 is then closed and steam alone is permitted tocontinue to flow into the vulcanizer until a temperature of 290 isobtained therein, at which time the pressure Will be 120125 pounds, andthis condition is maintained for about 5 minutes. In the operation asthus far described the unvulcanized rubber of the tubes 12 softens underthe eflect of the heat and concurrently is compressed by the compositefluid, With the result that all air entrapped Within the tube is greatlyreduced in volume and the tubes are compacted against the mandrels.

The valve 21 in the vent-pipe 21 is then opened for a time to permit theescape of com posite fluid to reduce the pressure thereof in thevulcanizer, the valve 27 remaining open to maintain the vulcanizingtemperature therein. When, after 5 or 6 minutes, the pressure hasdropped to about 55 pounds, the vent-pipe is closed, and the drain pipe28 is opened to permit the escape of any Water of condensation from thevulcanizer, through the steam trap 29, and approximately the thenexisting condition of temperature and pressure is maintained in thevulcanizer until the Work is completely vulcanized by con trol of thesteam inlet, although some of the air remaining in the vulcanizerescapes the steam trap.

At the end of the vulcanization the valve 27 is completely closed andthe valves 2]. and 22 are opened to vent the vulcanizer, after which thevulcanizer is opened and the Work removed, and the operation asdescribed is repeated.

The concurrent injection of the air and steam from the beginning assuresthat the Work will be adequately compressed as it softens, before asurface skin has been vulcanized thereon, as is likely to occur When thesteam in substantial quantity is admitted to the vulcanizer before theair. Removal of the air from the vulcanizer after vulcaniza tion startsavoids the possibility of oxidation of the rubber, and expeditesvulcanization, since better heat transfer is obtained from steam alonethan from an air-steam mixture.

The initial mixing of the steam and air by means of the injector, andalso the Withdrawal of air from the vulcanizerand the circulation of themixture through the vulcanizer by means of the injector, assures auniform mixture, which is to say a uniform distribution of each of thefluids throughout the interior of the vulcanizer so that local coolspots or air pockets are avoided.

Modifications of my invention are possible within the scope of theappended claims.

I claim:

1. The method of vulcanizing rubber articles Which comprises enclosingthe articles in a vulcanizer, mixing a heating fluid and a pressurefluid, conducting the mixture into the vulcanizer the rubber articlestherein be ing exposed to the mixture, and concurrently Withdrawingfluid from the vulcanizer and adding it to the mixture'of fluids passinginto the vulcanizer.

2. A method as defined in claim 1 in Which fluid is Withdrawn from thevulcanizer and added to the mixture of fluids passing into thevulcanizer, in part, at least, by the kinetic energy of the saidmixture.

8. The method of vulcanizing externally unconfined rubber articles Whichcomprises applying to the articles a mixture of air and steam andthereafter lowering the pressure While maintaining a vulcanizingtemperature by replacing a part of the mixture With steam.

4. In a vulcanizer the combination of a vulcanizing receptacle having aninlet and outlet, a piping circuit connecting said inlet and outlet, andmeans for admitting fluid pressure to said circuit, said means being soarranged that the admission of said fluid induces a circulation of fluidthrough the vulcanizing receptacle and piping circuit.

5. In a vulcanizer the combination of a vulcanizing receptacle, an inletand an outlet manifold therefor, a piping circuit connecting said inletand outlet manifolds, an injector in said circuit, and a fluid pressureline so connected With said injector as to induce a circulation of fluidWithin the vulcanizing receptacle and piping circuit When pressure fluidis admitted to the injector.

6. In combination, a vulcanizing receptacle having an inlet and anoutlet, a circuit of piping connecting said inlet and outlet, aninjector in said piping circuit, and tWo pressure-fluid lines connectedWith said piping circuit in such relation to the injector as to causefluids flowing therefrom to the injector to be intimately admixed inpassing therethrough.

In Witness whereof I have hereunto set my hand this 5th day of July,1928.

ERNEST BLAKER.

